Orange Sulphur

Orange Sulphur (Colias eurytheme) is in the Whites, Yellows, and Sulphurs family (Pieridae). Across the U.S., iNaturalist users have logged 52,884 research-grade observations of it in our sample, peaking in October.

Seasonal pattern in the national data: summer visitor / breeder. Counts also reflect when people are out photographing, so compare months within a state rather than across states.

When to photograph Orange Sulphur: observations by month (U.S.)

About Orange Sulphur

Colias eurytheme, the orange sulphur, also known as the alfalfa butterfly and in its larval stage as the alfalfa caterpillar, is a butterfly of the family Pieridae, where it belongs to the lowland group of "clouded yellows and sulphurs" subfamily Coliadinae. It is found throughout North America from southern Canada to Mexico, but is absent from the central and southeastern United States.From Wikipedia via iNaturalist — article, CC BY-SA.

Orange Sulphur by state

Main season = months with at least 30% of the state's peak-month count.

Related butterflies (Whites, Yellows, and Sulphurs)

Small WhitePieris rapae

Cloudless SulphurPhoebis sennae

Sleepy OrangeEurema nicippe

Checkered WhitePontia protodice

Dainty SulphurNathalis iole

Little YellowEurema lisa

Clouded SulphurColias philodice

Southern DogfaceZerene cesonia

Photography tips

• Butterflies are sluggish on cool mornings — the best time for close approaches.
• Keep the sensor parallel to the wings for edge-to-edge sharpness.
• Nectar plants in bloom are reliable places to wait.

FAQ